Why does my AC drop into fan mode when temp has not been reached yet?

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Good question. I'm not sure. I live in a condo on the third floor. The HVAC unit is inside my condo. I don't have one of those big AC fan units that you typically see in someones backyard. Everything is self contained inside my condo. On my thermostat, I have a fan setting that can be either on or off. I always have it set to OFF. Then I have another switch for heat or AC. Right now it's set to AC. When the AC comes on, I can hear what I think is the blower motor pushing the cool air through the vents. When there is no issue, once the temp is reached, I can hear a click from the themostat, and a minute later, everything shuts down. But when the issue arises, I hear a little clunk coming from the HVAC unit. There is no click coming from the thermostat. The AC part turns off and I believe the blower motor is still running. When this happens, it's almost the equivalent of me having the fan position set to on even though it's really set to off. So that's the best that I can explain it. Based on that description, I can let you determine if it's the indoor or outdoor fan staying on. Thanks.
 
FYI, I think we all thought you had a more typical furnace with a/c coil and outside free standing compressor, but it seems you have a through the wall a/c unit, which is a totally different kind of system.

Please clarify.
 
@Jeff Handy , here is a pic similar to what i have. The unit sits in a room in my condo. The air blows to the outside through a vent grille at the back of the unit.
 

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Wow, I am not familiar with that setup at all.

I see a water line going into it.

Does this same thing make your hot water?

Maybe this is a heat pump system?

Pros on here might recognize the labels on this.

Looks like it needs a specialized pro to diagnose, maibtain, and repair.

Maybe it needs filters cleaned or replaced, or the exterior vent cleaned?

Have you got a manual or maintenance instructions for it?

Does the Association check it and maintain it?
 
@Jeff Handy , the unit provides heat and AC. I have a separate hot water tank that provides the water. I don't have a manual for it but I did find an owner's manual online. I called Sears one year and the guy who came over to look at it said he wasn't familiar enough with the brand name to even consider doing any work on it. I replace the filters on a regular basis. I am not sure what a heat pump system is. Maybe that's what I have. I'm not sure. I know that in alot of condo units, this is the type of setup most units use. Each owner is therefore responsible for their own heating and cooling costs. Good thing is that even though it's been hot the last few days, the unit has not encountered the issue I'm reporting in this thread. Most likely because it's not been excessively hot outside. Thanks. Oh, forgot to mention, that pipe is a drainage pipe that carries drops of water to a drainage pipe. Usually water drips out when the AC is on but not when the heat is on. The pipe looks like a copper pipe in the pic but for my unit it's just a flexible transparent rubber tube. The condo association does not check or maintain it. The units are the responsibility of the condo owner .
 
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You have a separate hot water tank, but this big unit might be making the hot water, which is then stored in that tank.
Why else is there a water line going into the unit?
Maybe it is a boiler, and you have radiators or baseboard heating?

You should ask your association or neighbors about who they call for service.
If they all have that same setup, someone knows a company that is familiar with them.
 
Looks like a Water Sourced Heat Pump. I’m not familiar with Skymarks Chassis type WSHP units but I am familiar with the Whalen that are much more common in my area.

If the compressor is turning off before it’s set temperature is reached then it could be locking itself out on high pressure, low pressure, internal compressor safety, or condensate overflow safety. I’m not sure if your unit will have all those safeties though so some may not apply in your instance.

Are other people in the building having issues? If they are then I would contact the strata company and alert them that there may be a cooling tower issue or loop issue. They will also know who services the buildings common area equipment (boilers, domestic hot water, tower, electrical vault AC, sump pumps, etc) those are the people that would best be suited to service your heat pump. Because they know the building and probably have a set of building keys at their office they will be able to better troubleshoot your unit. For instance, some buildings operate a heating season and a cooling season and those buildings tennents will not ba able to operate their cooling without issues resulting unless the building has switched over to its cooling season. If your building is controlled by DDC then they will most likely have access to the interface in the event that they need to view parameters.

As a general rule of thumb, a typical residential technician or company like Sears would not be familiar enough with your unit for them to properly work on it. You will either need to find a company that services commercial equipment or best option is to use the buildings current service provider. A commercial company’s hourly rate is often higher but their techs should be properly trained on that equipment and familiar with towers and how they operate.

It’s hard to narrow down exactly where your issue is, if it’s a loop issue then the rest of the building will probably also have mentioned it to the concierge and he would be aware of it by now. If it’s a plugged condensate drain, low pressure or high pressure safety then it could show signs like you describe (depending on how the units logic is programmed to operate).

Before you call a tech you will want to see if the condensate drain line is clear and free, check that you have a clean filter installed, check that your supply and return water lines to the heat pump unit are open, contact the concierge or strata manager to see if this is a global building issue. After checking those items then it is time to call a technician to continue troubleshooting from on site. It’s hard to diagnose a failed capacitor, dirty condenser, or other cause of issue without getting a trained set of hands on it unfortunately.
 
Thanks again for all your help. I think I've done all I'm comfortable with doing...which is just the bare basics. As mentioned, the issue has not returned. But I thinks that’s due to the weather outside not being extremely hot. I'll track down a technician when I get a chance to get some referrals from my neighbours. Right now, things are pretty much shut down here.
 
If you have a concierge then ask them who provides the service on the cooling tower on the building. If you don’t have a concierge then you will need to contact the property manager. Honestly they are the best people to service your in suite equipment. If for some reason you had a bad experience with a technician from that company and that is the reason that you started looking around at different companies then call that company and let them know you would prefer a different technician to service your suite. Keep doing that until you find one that you like and request them EVERY time. Each technician comes with their own abilities and level of standards. There can be every type of technician working at the same company so there is usually no need to move your business elsewhere until you’ve exhausted your possibilities (unless there is a corporate level issue that is out of the technicians control, such as billing related issue).

Like a car mechanic, once you find a good one you hang onto them for dear life and don’t let them go.
 
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